Translation guide
Describes behavior, speech, or attitudes typical of a child, often with negative connotations of immaturity. Japanese offers several words and phrases depending on whether you mean 'innocently childlike' or 'immaturely childish'.
To describe someone or something as immature, silly, or acting below their age, often with a critical tone.
The most direct equivalent for 'childish' in a negative sense. Implies immaturity, lack of sophistication, or pettiness. Commonly used for behavior, ideas, or arguments.
彼の考え方は幼稚だ。
His way of thinking is childish.
そんな幼稚な言い訳はやめて。
Stop making such childish excuses.
Literally 'child-like', but often used negatively to mean 'childish' or 'immature'. Can also be neutral depending on context, but usually carries a slight negative nuance when referring to adults.
彼はもう30歳なのに、子供っぽいところがある。
He's already 30, but he has a childish side.
その子供っぽい態度を直したほうがいい。
You should fix that childish attitude.
Means 'unbecoming of an adult', 'immature', or 'childish'. Used when someone fails to act their age, especially in situations requiring maturity.
そんなことで怒るなんて大人げない。
It's childish to get angry over something like that.
大人げない喧嘩はやめましょう。
Let's stop this childish fight.
To describe something as charmingly innocent, naive, or reminiscent of a child's pure qualities, without negative judgment.
Means 'innocent', 'naive', or 'childlike' in a positive sense. Often used for a pure, unspoiled nature, but can sometimes imply a lack of worldly knowledge.
彼女の無邪気な笑顔が好きだ。
I love her innocent smile.
子供の無邪気な質問に答えるのは難しい。
It's hard to answer children's innocent questions.
Describes an innocent, artless, childlike charm, often used for appearance or expressions. More literary or poetic than 無邪気.
Means 'pure-hearted', 'naive', or 'innocent'. Emphasizes purity of heart, often used in more formal or written contexts.
To describe the way someone speaks as childish, either because they use baby talk or because their language is unsophisticated.
Refers to 'baby talk' or words used by/for young children. Not inherently negative, but using it as an adult can be seen as childish.
大人が幼児語を使うのは少し変だ。
It's a bit weird for adults to use baby talk.
Literally 'insufficient tongue', meaning a lisping or childish way of speaking. Often used to describe cute but immature speech.
彼女の舌足らずな話し方が可愛い。
Her lisping way of speaking is cute.
To describe actions that are silly, immature, or typical of a child's mischief.
Means 'mischief' or 'prank'. While not always negative, it can imply childish behavior when done by adults.
彼はいつも悪戯ばかりしている。
He's always playing childish pranks.
Slangy, from ガキ (brat). Means 'bratty' or 'childish' in a rough, derogatory way. Used mainly in casual speech.
ガキっぽい冗談はやめてくれ。
Cut out the childish jokes.
幼稚 (ようち) is the most direct and common for 'childish' in a negative sense, implying immaturity. 子供っぽい (こどもっぽい) can be neutral or negative depending on context, often describing appearance or behavior that resembles a child's. 大人げない (おとなげない) specifically criticizes someone for not acting their age, focusing on the lack of adult maturity.
Directly translating 'childish' as 子供の (こどもの) or 子供のような (こどものような) is usually unnatural. These mean 'child's' or 'like a child' and lack the negative nuance of 'childish' unless context makes it clear. Use 幼稚 or 子供っぽい instead.
彼女のあどけない寝顔を見ていると癒される。
Looking at her innocent sleeping face is soothing.
彼の純真な性格は周りの人を惹きつける。
His innocent personality attracts people around him.